Its too risky to let people test ride bikes, they go down they get damaged. In a car you would have to bassicly try to tip the thing over. But yeah Ive never heard of a dealership not letting you sit on the bike thats ridiculous. But if you know how big of a bike youre getting unless you are a pretty experienced rider I dont think you'll find much of a difference in performance, its ergonomics you want to worry about so just sitting on them should be enough.